Re: Controling a slit system with 2 hard and 4 soft motorrs

[Mark Rivers <rivers@cars.uchicago.edu>]

Hi Torsten,


Whether or not there is problem with collision depends on the mechanical design of the slits.  We generally have slits where the opposing blades are not in exactly the same plane, so that they can overlap, and negative widths are allowed.  This is generally a better design when one wants to make very small slit sizes, because if they can collide then they can never be "completely" closed.


Mark



________________________________
From: tech-talk-bounces@aps.anl.gov <tech-talk-bounces@aps.anl.gov> on behalf of Torsten Bögershausen <torsten.bogershausen@esss.se>
Sent: Friday, March 16, 2018 2:28 AM
To: Mooney, Tim M.; Goetze, Kurt A.; Tech-talk@aps.anl.gov; Tobias.Richter@esss.se; Pearson, Matthew R.
Subject: Re: Controling a slit system with 2 hard and 4 soft motorrs

Thanks everybody for the fast answers-
I think I was looking for "2slit_soft.vdb, which uses soft motor records,
instead of ao records, for center and width."

The good news: I got it working!
There is one question about the collision avoidance:
If the Gap is 0 and the slit is closed, and I move the center
there seems to be the risk for a collision, or better said,
that one blade is slightly started earlier and "pusshing" the other
one. I am not sure if this is a real-life problem.

The other thing is that I need to check the calculation of the
soft limits for the virtual motors.
The most obvious is that the rule "Gap > 0" is not there.
(And the other calculations need to be checked)
I'll set up a system with a simulator.

And of course, we are setting up a system as well,
where the synchronization is done in the motor controller.



On 08/03/18 18:20, Mooney, Tim M. wrote:
> There is also, in the optics module, 2slit_soft.vdb, which uses soft motor
> records, instead of ao records, for center and width.
>
>
> Tim Mooney (mooney@aps.anl.gov) (630)252-5417
> Beamline Controls Group (www.aps.anl.gov<http://www.aps.anl.gov>)
> Advanced Photon Source, Argonne National Lab
>
> -------------------------------------------------------------------------------
> *From:* tech-talk-bounces@aps.anl.gov <tech-talk-bounces@aps.anl.gov> on behalf
> of Goetze, Kurt A. <goetze@aps.anl.gov>
> *Sent:* Thursday, March 8, 2018 10:51:13 AM
> *To:* Torsten Bögershausen; Tech-talk@aps.anl.gov
> *Subject:* RE: Controling a slit system with 2 hard and 4 soft motorrs
> Hi Torsten,
>
> The synApps optics module has support for this type of thing:
>
> https://github.com/epics-modules/optics/blob/master/opticsApp/Db/2slit.db
>
> Kurt
>
> -----Original Message-----
> From: tech-talk-bounces@aps.anl.gov [mailto:tech-talk-bounces@aps.anl.gov] On
> Behalf Of Torsten Bögershausen
> Sent: Thursday, March 08, 2018 10:40 AM
> To: Tech-talk@aps.anl.gov
> Subject: Controling a slit system with 2 hard and 4 soft motorrs
>
> Hej motorists,
>
> I recently learned about the transform record, which can be used to control a
> slit with 2 physical axes in the way that you can set the values for GAP and
> CENTER and the position of the physical blades are calculated. (Or vice versa)
>
> Does anybody have a super-duper-luxus template file which uses 4 soft motors
> together with some calc and transform records ?
>
> Thanks in advance
> /Torsten